The EGAD (Electronic Grant Application Development) project is reaching a stage in its implementation where it is important to have some understanding of how information will flow. Many of the information pathways in the old grant review system had been implemented by moving stacks of applications from one room to another in the Westwood building. We have been able to keep with the starting idea of the EGAD project that all information flow should be electronic. There are, nevertheless, certain steps in the process where human intervention must occur. A search was made for a suitable computer tool for modeling this mixed type of process. A commercial package, Stella II, on the Macintosh was found. The structure of the electronic grant review process was represented in the language of Stella II. Simulations for a number of parameters and conditions have been made. Three conclusions are clear from the simulations: 1) The quality of the incoming grant applications is paramount. If more than 15% of the applications have to be corrected then the performance of the systems will be poor. The solution to this problem is to strengthen the checking components of the grant formulation program run by the applicants and their institutions to make sure that most applications are correct when received at the NIH. 2) The simulation suggests that the cutoff date be the last date for getting an acceptable application into the EGAD system. This shifts the burden of correctness of an application from the NIH to the applicants and their institution. 3) There are two steps in the grant acceptance and assignment process where human intervention is required; determining its errors can be corrected and assigning applications manually to study sections. If the error rate for applications is less than 5% then existing manpower levels will produce acceptable system performance. Similarly the system will perform well if only 10 to 15% of the acceptable applications have to be assigned to study section by human intervention. Simulations of other aspects of the grant application, review and grant award process will be conducted in the next months.